On the Wine mailing list, there is some interesting information on Leopard's apparent ability to load basic Windows binaries. "When tracking down a crash in the kernel32 loader test, Dmitry found a bug in the Mac OS loader when Wine tried to load his dummy PE file. Upon further research I found that the Mac loader seems to have its own undocumented PE loader built in. I did some further testing with a Windows binary and got some really interesting results." The first thought was that this was a remnant from Mac OS X' EFI support, but upon further investigation, this really seems like new, Leopard-specific behaviour: "This is new to Leopard. On Tiger, dlopen rejects PE files as expected. The Wine testing that Steven was originally trying to do would probably not crash on Tiger." Apparently, Apple is trying its best to hide this behaviour.

I don't have anything really useful to contribute to this discussion, but since it's an opportunity to cast some derision Microsoft's way...

If there is a binary file format worse than Mach-O, it's PE. Yes, it's an extension of COFF, but COFF wasn't that great and PE is a _really_ big and hairy extension. It's suck-tasticness boggles the mind really.

ELF isn't perfect, but it's an absolute shining pinnacle of virtue in comparison to either Mach-O or PE.